How do we have the expiry date flow into SAP for each HU on an ASN?

We currently are utilizing the external number range and using ASNs for inbound deliveiries from a vendor. The vendor is transmitting expiry date per HU, but our system is only capturing a single expiry date and applying to all the HUs of the same material on that PO. How can we have the expriy date flow into SAP on the individual HUs? This is causing QA release and traceability issues.